I have a problem. My wife seems to have a hard time orgasming

Ok, so long story short, I'm happily married now to the girl that I dated for the latter half of college. When we began having sexual relations, initially, and I literally mean for like the first week we had sex, she would orgasm almost every time we had sex. She seemed surprised because apparently she has a lot of problems orgasming and kind of warned me not to get scared or anything if the frequency of her orgasms fell coz thats how she usually was. Sure enough the warning turned into a self fulfilling prophecy and now, four years later she seldom cums during sex (maybe once every month) and at other times I help her cum (oral, finger, etc, maybe twice a week) and the rest of the time she's content with just me getting off. In fact, so much so that she doesn't even want to try "coz it's too much work", etc. And that it is. It really takes a while to get her off. Also, she never has G-spot orgasms. She loves it when I rub it, but the only time she had one was initially in our relationship during some finger stimulation and she ended up squirting. I told her it's ok and stuff but she was visibly embarrassed and hasn't had one since. I've approached the subject a few times but she almost always doesn't want to talk about it.

So what can I do to get her to orgasm more frequently? We've tried bondage, roleplaying, sexgames, acting out adult movies (as they progressed) and a shitload of other physical stuff, which now makes me feel that maybe the issue is emotional and not physical. She is kind of a control freak, could that be why she just doesn't let herself go as often as she would like? I don't know. Any suggestions?

HELP!